The invention relates to a tension roller for a belt drive, of the type consisting of a supporting member eccentrically pivoted on a pivot stud and restrained by a tension spring. The support member has a roller sleeve rotatably disposed thereon by way of a bearing. The support member is formed with a cylindrical interior space limited by side walls, and containing the tension spring. Bores for the pivot stud are disposed in the side walls eccentric to the axis of rotation of the tension roller.
A tension roller of this type is depicted in the drawings of German patent document DE-OS No. 25 24 744. As illustrated therein, the design consists of a cup-shaped member and a cover plate. The bottom of the cup-shaped member and the cover plate have eccentrically disposed bores for a pivot stud. The bore is formed after the member and plate are joined. It is considerably more expensive and difficult to align the bores if they are formed individually in the member and plate. The ball bearing race, which is placed directly in the sleeve of the supporting member, and the weld seam are shown as being formed of metallic stock. Additionally, the known tension roller has a stop pin which must be separately made and installed and limits the swinging motion of the supporting member about the pivot stud.
Another disadvantage of this design is that both free ends of the tension spring are axially offset and, on assembly, must be inserted in corresponding bores of the supporting member pivot stud. This known tension roller is extremely costly to manufacture and assemble, resulting in a functional but expensive product.